Hi Kevin,
I went towards Mixbus because of the price.
Though I did not yet go deeply into it ,to answer your demand concerning midi ins and outs : yes you can ,I mused around with Diva and with the sampled pianos from Digital Sound Factory using Rapture Pro and for sure you can play.
Didn't go into editing ,and for sure,I will have to follow the owner's manual because Mixbus is clearly less intuitive than Sonar in this area.
Also it is quite demanding to the CPU ,but while the latency announced is not good,the practical use of softsynth is quite ok ,no problems if you want to add a synth part to the audio material.
The Gui is appealing to me because I like to have the console view being more important than the track view.
Routing is quite intuitive by the way.
So hope it helps.
Mixbus seems to be usable as a daw but I think you cannot do everything with it.
I actually agree with bdickens and I have the same feelings.
I am also trying a little bit Reaper which seems to be really efficient when it comes to CPU optimisation.
Personnaly ,I will cary on with Sonar,try to learn to get what I can from Mixbus,and I am really looking towards an offer from Magix but not the one concerning Samplitude but ,the Vegas one which is quite appealing,though one hundred here and one hundred and a half there makes a lot of monney spent at the end......
All the best.
Olivier.